Unfaithfully Yours

Claude Eastman, a renowned composer and conductor, marries Daniella. While traveling after the ceremony, he sends a message to his friend Norman Robbins asking him to keep an eye on his wife. The message is garbled by Claude's Italian valet, Giuseppe, sowing confusion from the start.

Norman Robbins, unsettled by the garbled warning, hires private detective Keller to look into Daniella's behavior. Keller accepts the assignment and begins quietly observing the couple. The hire sets the stage for later revelations.

Keller's report arrives with a fuzzy video suggesting Daniella had an assignation with a man wearing Argyle socks who resembles Maxmillian Stein. The finding appears to confirm an infidelity, at least in appearance. Daniella is painted as the unfaithful spouse based on the footage.

In a twist, it becomes clear that Max did not meet Daniella at all. He had used Claude's flat for an assignation with Carla, Norman's wife. The misinterpretation shifts suspicion away from Daniella for the moment.

Claude tries to stage a surprise by bringing Max and Daniella together to prove his supposed knowledge of their affair. The plan leads Max and Carla to believe Claude is aware of their relationship, making them uneasy. The seed of jealousy drives Claude's next actions.

When Max eventually meets Daniella, it is at a restaurant. Overcome by jealousy, Claude ends up dueling Max with violins by playing Vittorio Monti's Csárdás. The dramatic display intensifies the feud and makes the affair painfully public.

Claude directly confronts Daniella, pressing her about the alleged infidelity. Daniella feels guilty about keeping the affair secret from her husband, admitting the emotional strain of the situation but not fully clarifying the truth.

Claude then confronts Max privately, escalating the strain between master and protégé. Max apologizes for using Claude's flat for the encounter, but does not explicitly clear up Carla's involvement or the misdirection around Daniella.

Daniella feels guilty about keeping the affair secret from Claude and continues to weigh the consequences of the deception. Max apologizes only for using Claude's flat for the affair, with no direct admission about Carla's involvement. The lack of full clarity fuels Claude's mounting jealousy.

As he conducts Tchaikovsky's Violin Concerto, Claude envisions a plan to kill Daniella and frame Max for the murder. His mind swirls with the idea, and a chilling laugh signals the darkness behind his jealousy. The murder plot remains just out of reach as unforeseen events intervene.

Keller realizes his mistake after spotting Carla leaving Claude's apartment on the surveillance tape. The misidentified target becomes the hinge that could derail Claude's plan. He resolves to confront the situation more directly.

After failing to reach Claude at the concert, Keller goes to Claude's flat and interrupts him as he struggles to carry out the murder plan. The confrontation prevents the immediate crime and forces Claude to face reality. Daniella's fate hangs in the balance as emotions surge.

Daniella is initially furious when she learns the truth, mainly over Claude's belief in her infidelity. She leaves, but Claude chases after her and explains that he loves her and cannot shake his jealousy. The couple reconciles, with a fragile but hopeful bond formed by honesty.